The first item on your planning should be to figure out where you would like to go. Write down the days you are able to go. Make a list of the days. FIll in the days with the city and country you want to visit on each day.
Often the first two days will be travel if you are going on an international trip. For example: going to Europe the first day is normally in the airplane…since you are going into a new time zone you will find yourself in day two before your actual touring day begins. Going west will be different so look at time zones and date lines and figure out which days will be eaten up with travel either getting there or returning home.
Snap Easy Tip: Whatever time you arrive at your destination DO NOT go to sleep until at least 8:30 pm. Push yourself or you will not acclimate to the new timezone. I find it better to arrive in the afternoon instead of morning. It is a LONG day if you are pushing to stay awake.
I would recommend that you not try to travel to more than one country per week. You will spend most of your time traveling and not enjoying the country you are in! If you have a couple weeks and you are traveling to a nearby country you might take a train. However, if the next country is a long distance you would spend your time better taking a plane. There are very cheap flights within Europe.